Consolidated Statements of Equity - USD ($) $ in Thousands	Simon Property Group, L.P. Simon (Managing General Partner)	Simon Property Group, L.P. Limited Partners	Simon Property Group, L.P. Preferred Stock	Simon Property Group, L.P. Noncontrolling Interests	Simon Property Group, L.P.	Preferred Stock	Common Stock	Accumulated Other Comprehensive Income (Loss)	Capital in Excess of Par Value	Accumulated Deficit	Common Stock Held in Treasury	Noncontrolling Interests	Total
Balance at Dec. 31, 2018						$ 42,748	$ 32	$ (126,017)	$ 9,700,418	$ (4,893,069)	$ (1,427,431)	$ 500,275	$ 3,796,956
Balance at Dec. 31, 2018	$ 3,253,933	$ 492,877	$ 42,748	$ 7,398	$ 3,796,956
Increase (Decrease) in Stockholders' Equity
Exchange of limited partner units									253			(253)
Series J preferred stock premium amortization			(82)		(82)	(82)							(82)
Limited partner units exchanged to common units	253	(253)
Redemption of limited partner units	(127)	(8)			(135)				(127)			(8)	(135)
Amortization of stock incentive	1,309				1,309				1,309				1,309
Treasury stock purchase											(7,628)		(7,628)
Treasury unit purchase	(7,628)				(7,628)
Long-term incentive performance units		3,701			3,701							3,701	3,701
Issuance of unit equivalents and other	(1,756)	(2)			(1,758)				1	(1,507)	(250)	(2)	(1,758)
Unrealized (loss) gain on derivative hedge agreements	8,115	1,227			9,342			8,115				1,227	9,342
Currency translation adjustments	(4,130)	(614)			(4,744)			(4,130)				(614)	(4,744)
Changes in available-for-sale securities and other	125	19			144			125				19	144
Net (gain) loss reclassified from accumulated other comprehensive loss into earnings	945	143			1,088			945				143	1,088
Other comprehensive income	5,055	775			5,830			5,055				775	5,830
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	4,167	(4,167)							4,167			(4,167)
Distributions to common stockholders and limited partners, excluding Operating Partnership preferred interests										(634,222)		(96,010)	(730,232)
Distributions to other noncontrolling interest partners												(552)	(552)
Distributions to limited partners, excluding preferred interests classified as temporary equity	(633,388)	(96,010)	(834)	(552)	(730,784)
Net income, excluding preferred distributions on temporary equity preferred units and amounts attributable to noncontrolling redeemable interests in properties	548,475	83,076	834	148	632,533					549,309		83,224	632,533
Balance at Mar. 31, 2019						42,666	32	(120,962)	9,706,021	(4,979,489)	(1,435,309)	486,983	3,699,942
Balance at Mar. 31, 2019	3,170,293	479,989	42,666	6,994	3,699,942
Balance at Dec. 31, 2018						42,748	32	(126,017)	9,700,418	(4,893,069)	(1,427,431)	500,275	3,796,956
Balance at Dec. 31, 2018	3,253,933	492,877	42,748	7,398	3,796,956
Increase (Decrease) in Stockholders' Equity
Unrealized (loss) gain on derivative hedge agreements					15,227								15,227
Currency translation adjustments					(14,656)								(14,656)
Changes in available-for-sale securities and other					1,151								1,151
Net (gain) loss reclassified from accumulated other comprehensive loss into earnings					3,261								3,261
Balance at Sep. 30, 2019						42,502	32	(121,596)	9,748,255	(5,223,093)	(1,773,571)	407,623	3,080,152
Balance at Sep. 30, 2019	2,630,027	400,716	42,502	6,907	3,080,152
Balance at Mar. 31, 2019						42,666	32	(120,962)	9,706,021	(4,979,489)	(1,435,309)	486,983	3,699,942
Balance at Mar. 31, 2019	3,170,293	479,989	42,666	6,994	3,699,942
Increase (Decrease) in Stockholders' Equity
Series J preferred stock premium amortization			(82)		(82)	(82)							(82)
Stock incentive program									(16,340)		16,340
Amortization of stock incentive	5,098				5,098				5,098				5,098
Treasury stock purchase											(173,630)		(173,630)
Treasury unit purchase	(173,630)				(173,630)
Long-term incentive performance units		7,721			7,721							7,721	7,721
Issuance of unit equivalents and other	(7,960)	1		69	(7,890)				11	(5,265)	(2,706)	70	(7,890)
Unrealized (loss) gain on derivative hedge agreements	(6,113)	(909)			(7,022)			(6,113)				(909)	(7,022)
Currency translation adjustments	(3,078)	(545)			(3,623)			(3,078)				(545)	(3,623)
Changes in available-for-sale securities and other	468	71			539			468				71	539
Net (gain) loss reclassified from accumulated other comprehensive loss into earnings	942	144			1,086			942				144	1,086
Other comprehensive income	(7,781)	(1,239)			(9,020)			(7,781)				(1,239)	(9,020)
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	28,588	(28,588)							28,588			(28,588)
Distributions to common stockholders and limited partners, excluding Operating Partnership preferred interests										(633,686)		(95,977)	(729,663)
Distributions to other noncontrolling interest partners												(455)	(455)
Distributions to limited partners, excluding preferred interests classified as temporary equity	(632,851)	(95,977)	(835)	(455)	(730,118)
Net income, excluding preferred distributions on temporary equity preferred units and amounts attributable to noncontrolling redeemable interests in properties	495,324	75,066	835	426	571,651					496,159		75,492	571,651
Balance at Jun. 30, 2019						42,584	32	(128,743)	9,723,378	(5,122,281)	(1,595,305)	444,007	3,363,672
Balance at Jun. 30, 2019	2,877,081	436,973	42,584	7,034	3,363,672
Increase (Decrease) in Stockholders' Equity
Series J preferred stock premium amortization			(82)		(82)	(82)							(82)
Stock incentive program									(249)		249
Redemption of limited partner units	(4,160)	(254)			(4,414)				(4,160)			(254)	(4,414)
Amortization of stock incentive	3,042				3,042				3,042				3,042
Treasury stock purchase											(178,515)		(178,515)
Treasury unit purchase	(178,515)				(178,515)
Long-term incentive performance units		4,664			4,664							4,664	4,664
Issuance of unit equivalents and other	(136)			35	(101)				7	(143)		35	(101)
Unrealized (loss) gain on derivative hedge agreements	11,186	1,721			12,907			11,186				1,721	12,907
Currency translation adjustments	(5,388)	(901)			(6,288)			(5,388)				(901)	(6,288)
Changes in available-for-sale securities and other	406	62			468			406				62	468
Net (gain) loss reclassified from accumulated other comprehensive loss into earnings	943	144			1,087			943				144	1,087
Other comprehensive income	7,147	1,026			8,173			7,147				1,026	8,173
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	26,237	(26,237)							26,237			(26,237)
Distributions to common stockholders and limited partners, excluding Operating Partnership preferred interests										(645,757)		(98,275)	(744,032)
Distributions to other noncontrolling interest partners												(495)	(495)
Distributions to limited partners, excluding preferred interests classified as temporary equity	(644,923)	(98,275)	(834)	(495)	(744,527)
Net income, excluding preferred distributions on temporary equity preferred units and amounts attributable to noncontrolling redeemable interests in properties	544,254	82,819	834	333	628,240					545,088		83,152	628,240
Balance at Sep. 30, 2019						42,502	32	(121,596)	9,748,255	(5,223,093)	(1,773,571)	407,623	3,080,152
Balance at Sep. 30, 2019	2,630,027	400,716	42,502	6,907	3,080,152
Balance at Dec. 31, 2019						42,420	32	(118,604)	9,756,073	(5,379,952)	(1,773,571)	384,852	2,911,250
Balance at Dec. 31, 2019	2,483,978	378,339	42,420	6,513	2,911,250
Increase (Decrease) in Stockholders' Equity
Exchange of limited partner units									1,076			(1,076)
Series J preferred stock premium amortization			(82)		(82)	(82)							(82)
Limited partner units exchanged to common units	1,076	(1,076)
Redemption of limited partner units	(15,127)	(940)			(16,067)				(15,127)			(940)	(16,067)
Amortization of stock incentive	1,891				1,891				1,891				1,891
Treasury stock purchase											(152,589)		(152,589)
Treasury unit purchase	(152,589)				(152,589)
Long-term incentive performance units		4,987			4,987							4,987	4,987
Issuance of unit equivalents and other	3,316			26	3,342				29	3,287		26	3,342
Unrealized (loss) gain on derivative hedge agreements	19,510	2,963			22,473			19,510				2,963	22,473
Currency translation adjustments	(20,505)	(3,099)			(23,604)			(20,505)				(3,099)	(23,604)
Changes in available-for-sale securities and other	715	109			824			715				109	824
Net (gain) loss reclassified from accumulated other comprehensive loss into earnings	(417)	(63)			(480)			(417)				(63)	(480)
Other comprehensive income	(697)	(90)			(787)			(697)				(90)	(787)
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	24,233	(24,233)							24,233			(24,233)
Distributions to common stockholders and limited partners, excluding Operating Partnership preferred interests										(645,259)		(98,099)	(743,358)
Distributions to other noncontrolling interest partners												(3,167)	(3,167)
Distributions to limited partners, excluding preferred interests classified as temporary equity	(644,425)	(98,099)	(834)	(3,167)	(746,525)
Net income, excluding preferred distributions on temporary equity preferred units and amounts attributable to noncontrolling redeemable interests in properties	437,605	66,658	834	436	505,533					438,439		67,094	505,533
Balance at Mar. 31, 2020						42,338	32	(119,301)	9,768,175	(5,583,485)	(1,926,160)	329,354	2,510,953
Balance at Mar. 31, 2020	2,139,261	325,546	42,338	3,808	2,510,953
Balance at Dec. 31, 2019						42,420	32	(118,604)	9,756,073	(5,379,952)	(1,773,571)	384,852	2,911,250
Balance at Dec. 31, 2019	2,483,978	378,339	42,420	6,513	2,911,250
Increase (Decrease) in Stockholders' Equity
Unrealized (loss) gain on derivative hedge agreements					(51,034)								(51,034)
Currency translation adjustments					(18,983)								(18,983)
Changes in available-for-sale securities and other					245								245
Net (gain) loss reclassified from accumulated other comprehensive loss into earnings					(1,435)								(1,435)
Balance at Sep. 30, 2020						42,173	32	(180,468)	9,761,978	(5,953,166)	(1,917,698)	263,365	2,016,216
Balance at Sep. 30, 2020	1,710,678	259,797	42,173	3,568	2,016,216
Balance at Mar. 31, 2020						42,338	32	(119,301)	9,768,175	(5,583,485)	(1,926,160)	329,354	2,510,953
Balance at Mar. 31, 2020	2,139,261	325,546	42,338	3,808	2,510,953
Increase (Decrease) in Stockholders' Equity
Series J preferred stock premium amortization			(82)		(82)	(82)							(82)
Stock incentive program									(9,317)		9,317
Amortization of stock incentive	4,969				4,969				4,969				4,969
Long-term incentive performance units		3,229			3,229							3,229	3,229
Issuance of unit equivalents and other	22,899	(2)			22,897				1	23,753	(855)	(2)	22,897
Unrealized (loss) gain on derivative hedge agreements	(21,116)	(3,216)			(24,332)			(21,116)				(3,216)	(24,332)
Currency translation adjustments	(13,815)	(2,088)			(15,903)			(13,815)				(2,088)	(15,903)
Changes in available-for-sale securities and other	(479)	(73)			(552)			(479)				(73)	(552)
Net (gain) loss reclassified from accumulated other comprehensive loss into earnings	(415)	(63)			(478)			(415)				(63)	(478)
Other comprehensive income	(35,825)	(5,440)			(41,265)			(35,825)				(5,440)	(41,265)
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	(769)	769							(769)			769
Distributions to common stockholders and limited partners, excluding Operating Partnership preferred interests										(398,499)		(60,510)	(459,009)
Distributions to other noncontrolling interest partners												(244)	(244)
Distributions to limited partners, excluding preferred interests classified as temporary equity	(397,664)	(60,510)	(835)	(244)	(459,253)
Net income, excluding preferred distributions on temporary equity preferred units and amounts attributable to noncontrolling redeemable interests in properties	254,213	38,650	835	293	293,991					255,048		38,943	293,991
Balance at Jun. 30, 2020						42,256	32	(155,126)	9,763,059	(5,703,183)	(1,917,698)	306,099	2,335,439
Balance at Jun. 30, 2020	1,987,084	302,242	42,256	3,857	2,335,439
Increase (Decrease) in Stockholders' Equity
Exchange of limited partner units									403			(403)
Series J preferred stock premium amortization			(83)		(83)	(83)							(83)
Limited partner units exchanged to common units	403	(403)
Redemption of limited partner units	(36)	16			(20)				(36)			16	(20)
Amortization of stock incentive	2,594				2,594				2,594				2,594
Long-term incentive performance units		(4,004)			(4,004)							(4,004)	(4,004)
Issuance of unit equivalents and other	1,831	5			1,836				1	1,830		5	1,836
Unrealized (loss) gain on derivative hedge agreements	(42,683)	(6,492)			(49,175)			(42,683)				(6,492)	(49,175)
Currency translation adjustments	17,778	2,746			20,525			17,778				2,746	20,525
Changes in available-for-sale securities and other	(23)	(4)			(27)			(23)				(4)	(27)
Net (gain) loss reclassified from accumulated other comprehensive loss into earnings	(414)	(63)			(477)			(414)				(63)	(477)
Other comprehensive income	(25,342)	(3,813)			(29,155)			(25,342)				(3,813)	(29,155)
Adjustment to limited partners' interest from change in ownership in the Operating Partnership	(4,043)	4,043							(4,043)			4,043
Distributions to common stockholders and limited partners, excluding Operating Partnership preferred interests										(398,573)		(60,447)	(459,020)
Distributions to other noncontrolling interest partners												(43)	(43)
Distributions to limited partners, excluding preferred interests classified as temporary equity	(397,739)	(60,447)	(834)	(43)	(459,063)
Net income, excluding preferred distributions on temporary equity preferred units and amounts attributable to noncontrolling redeemable interests in properties	145,926	22,158	834	(246)	168,672					146,760		21,912	168,672
Balance at Sep. 30, 2020						$ 42,173	$ 32	$ (180,468)	$ 9,761,978	$ (5,953,166)	$ (1,917,698)	$ 263,365	$ 2,016,216
Balance at Sep. 30, 2020	$ 1,710,678	$ 259,797	$ 42,173	$ 3,568	$ 2,016,216